Model Development for Cable - Harnessed Beams

As designers aim to save on launch costs by using light-weight materials for space structures, the cable harnesses that are mounted to these structures make up a greater percentage of the structure’s mass than in past missions. Research has shown that the effects of cable harnesses on the dynamic response of space structures may be significant, but there is not yet a reliable model that can predict the changes in frequency response due to the structural mass of the cables. In this paper, the author describes the development of two models to determine the fundamental frequencies of cable-harnessed beams, one based on the Rayleigh-Ritz method and one based on the distributed transfer function method. In addition, the author discusses the discrepancy between experimental cable data and modeling a cable as an Euler-Bernoulli beam or string, and how the cable could be modeled more accurately. The author also presents the experimental data from the excitation of a cable-harnessed beam that will be used to validate the models, and what trends can be observed from the experimental data. With further development, this research will garner accurate models to accurately predict the natural frequencies and damping effects for cabled space structures.